Final answer:
To build muscular strength, it is important to exercise both muscles in a muscle pair equally to ensure balanced strength and prevent injuries.
Step-by-step explanation:
When exercising to build muscular strength, it is important to exercise both muscles in a muscle pair equally because they work together to move the bones in opposite directions. Muscles come in pairs, with one muscle acting as the flexor and the other as the extensor.
For example, in the arm, the biceps muscle is the flexor that closes the limb, and the triceps muscle is the extensor that opens the limb. By exercising both muscles in a pair, you can ensure balanced strength and prevent muscle imbalances that can lead to injuries.